1. Field of the Invention
The present invention relates to an all-in-one drawing apparatus which has a protractor integrated with horizontal and vertical rulers on a drawing board. The protractor slides on the horizontal ruler which acts as T-square being slidably attached to both ends of the board. The vertical ruler can pivot according to measured angles on the protractor portion and incorporates a pen in a holder adapted to move within a slot in the vertical ruler.
2. Description of the Related Art
The related art of interest describes various drawing board implements, but the art neither teaches nor suggests the all-in-one drawing apparatus of the present invention. The related art will be discussed in the order of perceived relevance to the present invention.
U.S. Pat. No. 3,795,053 issued on Mar. 5, 1974, to Dennis A. Burke describes a circular transparent combination drawing instrument containing features of a protractor, compass, ruler, and a triangle. The flat disc has its peripheral edge divided into degrees with degree marking holes at 5.degree. intervals. Sight guide lines define a series of concentric squares symmetrical about the center guide hole. The disc is subdivided into 45.degree. segments by straight rows of guide holes radiating from the center guide hole. It is suggested that the disc can be rotatably mounted within a circular member of a base member having a base surface flush with the base surface of the disc and with the base member provided with a straight edge. The utility of such a device would be that it would incorporate the straight edge required to construct lines and require only one pencil to construct circles. The suggested device is distinguishable because the disc is rotatable on the straight edge to draw circles.
U.S. Pat. No. 3,835,542 issued on Sep. 17, 1974, to Leslie L. DeMathe describes a mobile integral drafting instrument comprising a straight edge having a first clutch mechanism to provide vertical movement thereof on a drawing media, and a second clutch mechanism to provide a circular movement thereof for drawing free and predetermined angles, straight lines and curved lines without the aid of additional instruments. The drafting instrument is distinguishable for its clutch mechanims not required in the present invention.
U.S. Pat. No. 4,899,454 issued on Feb. 13, 1990, to John G. R. Francis describes a perspective drawing machine for a drafting table which includes vertical and horizontal straight edged supports together with drive mechanisms. The drafting machine is distinguishable for its drive mechanisms.
U.S. Pat. No. 3,925,899 issued on Dec. 16, 1975, and U.S. Pat. No. 4,004,347 issued on Jan. 25, 1977, to Sarah Hesse et al. describe a graphics instrument including a pair of coplanar scale members mounted for concentric mutual rotation. The outer scale member can be square or octagonal shaped with both members having extended ruled arms. One embodiment has releasable arms and locked with eccentric cam locks so as to function as a T-square. The devices are distinguishable for reliance on two concentric rotating members.
U.S. Pat. No. 4,351,117 issued on Sep. 28, 1982, to Earl R. Wade describes a drawing board apparatus designed for scaling off with a rose plate having its central axis centered on the drawing board which has a carriage frame supporting horizontal first and second drawing bars connected by vertical pivoting links. The first drawing bar suspends a T-square vertically. The second drawing bar has a scale strip. The apparatus is distinguishable for its centered rotating rose plate and the pair of linked drawing bars.
U.S. Pat. No. 4,462,168 issued on Jul. 31, 1984, to Thomas J. Lynch et al. describes a variable angle straight edge comprising an elongated rectanglar transparent plastic body with a printed, etched or scribed trapezoidal protractor proximate the left end having a wider width or offset for placing the pen for the origin. The device can be used upside down or made also for a left-handed draftsperson by placing the offset at the opposite end. The device is distinguishable for its limitation to drawing oblique lines without the use of a T-square.
U.S. Pat. No. 4,490,921 issued on Jan. 1, 1985, to William D. Woods et al. describes a six inch long drafting tool which is rectangular, transparent and scribed with different linear scales on opposite edges. A trapezoidal protractor is centered and based on the bottom scales. Cutouts for circles are on one side and squares, French curves, a triangle, and arrowhead points are on the opposite side. The tool is distinguishable for its combination of cutouts for geometrical figures with linear scales and a protractor.
U.S. Pat. No. 4,918,822 issued on Apr. 24, 1990, to Semond Levitt describes a perspective drafting apparatus combined with a drafting machine and board. A centerpiece has the conventional drafting machine and vertical scale in addition to a pair of slidable straight edges pivotally connected. The drafting board has wing pieces on each side with vertically spaced holes for perspective drawing. The elaborate drawing board with the centerpiece is distinguishable for its multiple elements and the absence of a protractor.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, an all-in-one drawing board solving the problem of obtaining accurate angled lines without resorting to manual manipulation of the drawing pen and the use of a separate protractor or triangles is desired.